1. Field of the Invention
The present invention relates to energy saving control of an image recording apparatus which has an interface with an external unit such as a personal computer and records an image on a record sheet based on image information inputted from an external unit through the interface.
2. Related Background Art
As an image recording apparatus of this type, a laser printer which uses an electrographic process has been known. Many laser printers have the following three types of operation modes.
First, a print mode in which a record sheet is transported and a print operation is carried out.
Secondly, a stand-by mode in which an immediate print operation is ready. For example, in a laser printer having a thermal fixing unit using a halogen heater, temperature control is effected to maintain the thermal fixing unit at a slightly lower temperature in the stand-by mode than a fixing temperature in the print mode.
Thirdly, a sleep mode which is set by a social demand in recent energy saving trend and in which a power consumption is further reduced than that in the stand-by mode.
Many prior art laser printers comprise video control means for generating bit map data for each pixel as a video signal from data described by a command scheme such as PDL (page description language) based on a record command from the external unit and record control means for recording an image represented by the video signal. The control of the operation modes is effected by the record control means. A command to shift to the sleep mode and return from the sleep mode is effected from the video control means to the record control means based on information from the external unit.
In the prior art sleep mode, however, since the energization and deenergization of the thermal fixing unit used in the laser printer are uniformly set, optimum energy saving control to fit a variety of operation states of the printer is not attained.
It is an object of the present invention to provide an image recording apparatus which permits optimum energy saving control for various operation states of the printer. In particular, it is an object of the invention to provide an image recording apparatus in which execution of energy saving modes is performed selectively.
An image recording apparatus in accordance with the present invention includes an image forming means, a fixing means, a cooling means and a control means. The image forming means is for forming an image on a recording medium on the basis of an image signal generated by an image signal generating unit. The fixing device is for heat-fixing the image formed on the recording medium; the cooling means is for cooling the inside of the apparatus. The control means is for selectively executing either a first economy mode, in which the cooling means is activated and the fixing means is inactivated on the basis of a command from the image signal generating unit, or a second economy mode in which both the cooling means and the fixing means are inactivated.
Other objects, advantages and effects of the present invention will be apparent from the accompanying drawings, following description and claims.